SEOUL, June 15 (Reuters) - South Korea’s Iranian crude oil imports fell in May to their lowest since January 2016 as South Korean buyers sought to reduce purchases of Iranian oil amid new U.S. sanctions on Iran.

In May, South Korea imported 758,903 tonnes of Iranian crude, or 179,444 barrels per day (bpd), versus 1.02 million tonnes last year, customs data showed on Friday. That was the lowest since January 2016 when South Korea imported 859,223 tonnes.

South Korea, the world’s fifth biggest crude importer, mainly buys an ultra-light oil known as condensate from Iran, however its intake of Iranian oil has been on the decline in recent months with the start of a new condensate splitter in Iran and lower production.

Against this backdrop, U.S. President Donald Trump said in early May that the United States would walk away from an international nuclear deal with Iran and impose renewed U.S. economic sanctions on Tehran, sparking concerns about buying Iranian oil.

South Korea said it would seek exemptions from the United States following the U.S. move. South Korea had previously managed to get a waiver on U.S. sanctions by curtailing its oil imports from Iran

For the first five months, South Korea’s oil imports from Iran fell 33 percent to 5.45 million tonnes, or 264,369 bpd, compared with 8.12 million tonnes in the same period last year, according to the customs data.

Overall, South Korea’s total May crude imports were 12.69 million tonnes, or roughly 3 million bpd, up 2.5 percent from 12.38 million tonnes last year.

On the other hand, South Korea’s imports of U.S. crude in May showed a nearly three-fold increase at 405,158 tonnes, or 95,800 bpd, from 141,162 tonnes a year ago. Oil shipments from Russia also jumped in May, up 78 percent to 922,664 tonnes, or 218,165 bpd, from last year.

In the first five months of 2018, South Korea imported 60.97 million tonnes of crude, or 2.96 million bpd, up 0.7 percent from 60.56 million tonnes during the same period in 2017, according to the data.

South Korea’s final May crude imports data will be released by state-run Korea National Oil Corp (KNOC) later this month.